Energy efficiency and
environmental issues...

Air Quality Overview

The main environmental issues related to air quality are:

Global warming caused mainly by carbon dioxide production as a consequence of burning fossil fuels. However, there are other greenhouse gases including methane.

Acid rain caused mainly by the production of sulphur dioxide and nitrogen oxides from fossil fuels and the internal combustion engine.

Ozone depletion caused by the production of gases that react with ozone. These include chemicals in some refrigerators, aerosol cans and fire extinguishers.

Chemical pollutants in the air. A number of chemicals have harmful or irritating effects and can be particularly of concern to asthma sufferers. For most air pollutants the main sources of emissions are from fossil fuel combustion.

An effective school environmental policy should focus on reducing its wider environmental impact by reducing energy usage and also on the quality of air within the school. The latter is related to the quality of ventilation and usage of chemicals such as cleaning agents.

Ventilation guidelines are included in the legally binding School Premises Regulations 1999. School premises regulations identify that all occupied areas in a school building should have controllable ventilation at a minimum of 3 litres of fresh air per second for each of the maximum number of persons the area will accommodate. At the same time all washrooms should be ventilated enough to ensure 6 changes of air per hour. Studies by BRE have found that 50%+ of primary school classrooms failed to achieve minimum air change rates.[2001] Carbon dioxide concentrations of up to 3000ppm have been found in many classrooms and this may affect student performance.

A school can also contribute positively overall to air quality by developing wildlife areas, utilising more plants internally and planting trees on the premises whilst at the same time seeking to influence the families of pupils to do likewise. Information on air quality improvement measures can be found here.

Trends

Since 1751 roughly 270 billion tons of carbon have been released to the atmosphere from the consumption of fossil fuels and cement production. Half of these emissions have occurred since the mid 1970s. The 1998 fossil-fuel emission estimate for global CO2 emissions, 6608 million metric tons of carbon, represents a 0.3% decline from 1997. This small 1997-98 decline is the first decline in the global record since a 1.6% decline from 1991-92.

Globally, liquid and solid fuels accounted for 77.7% of the emissions from fossil-fuel burning in 1998. Combustion of gas fuels (e.g., natural gas) accounted for 18.5% (1220 million metric tons of carbon) of the total emissions from fossil fuels in 1998 and reflects a gradually increasing global utilization of natural gas. Emissions from cement production fell slightly to 207 million metric tons of carbon, a twenty-fold increase since the 1920s. Emissions from gas flaring for 1998 were estimated to be 47 million metric tons of carbon, well below the levels of the 1970s. Collectively, emissions from cement production and gas flaring comprised 4% of total emissions for 1998.

Total carbon dioxide emissions in the United Kingdom have been virtually unchanged since 1980 and remain well below the 1973 and 1979 peaks. Emissions declined 19% from 1979 to 1984. After years of increases in emissions from liquid fuels and generally declining emissions from coal burning, emissions from both fuels began to decline simultaneously in 1974. Emissions from natural gas use grew rapidly in the late 1960s and have doubled since the mid 1970s. Natural-gas burning now accounts for 35% of total emissions of CO2. Fossil-fuel CO2 emissions from the United Kingdom in 1998 equalling 148 million metric tons of carbon, are comparable to emission levels of the 1950s. Since 1950, the United Kingdom has dropped from third to seventh in rank among fossil-fuel CO2 emitting nations.

However the largest emission increases from electricity and heat production in the EU in 2003 was in the UK (+10 million tonnes)

Greenhouse Gas Emissions UK - Down since 1990

The environmental impact of a typical school in carbon equivalent per pupil year. (Greening Britain's Schools Sustainability Study )

Information on Air Quality in the UK can be found at www.defra.gov.uk

Building Schools for the Future makes clear that in providing an even temperature for pupils there should also be good ventilation which should preferably be natural ventilation. However studies have shown that school users don’t often open windows to provide adequate ventilation and therefore mechanical means may be required. Staff in schools should be trained to utilise ventilation efficiently as part of their on going CPD programmes. Air conditioning is not usually required in schools and should be resisted where possible because of its high energy costs.